Comments on: (x,y,z,w) in OpenGL/Direct3D (Homogeneous Coordinates)

By: Andrew Harvey

Andrew Harvey — Sat, 13 Jun 2009 00:08:09 +0000

Yeh, that course looks great. I hope I can find space to do it.

By: Rupert

Rupert — Fri, 12 Jun 2009 16:30:45 +0000

If you are interested in learning more about this, you should take MATH5785 Geometry next time it runs

By: Andrew Harvey

Andrew Harvey — Wed, 03 Dec 2008 01:15:13 +0000

(I think, though am not sure) Because if you have a matrix A times a vector B of dimension 4, then the matrix A will need to have 4 columns for the multiplication to make sense, and it will have 4 rows (probably) because the resulting vector needs 4 rows. I’m not to sure but some perspective transformations utilise this.

By: _Felix

_Felix — Tue, 02 Dec 2008 21:11:01 +0000

OK, but why do matrices in openGL have sixteen values, rather than twelve? What are the other four?